In Louisiana, canvassers are now going door to door in affected neighborhoods to try to learn how many displaced residents have returned. But they also hope to find out many have left for good. And whether more may still follow.

"I think in the next year or two we are going to see a second wave of migration out of the city as people discover the return to normalcy just isn't meeting their needs," says John Logan, a sociologist at Brown University.

It's a sensitive subject to people like David Patin, a pastor who evacuated to Dallas along with many of his parishioners and now claims both cities as home.

"The New Orleans we left will never be the same, and most of our people know that," Patin says.

So while the decision to leave New Orleans was emotional for some — "It's not really fair to tell somebody they should feel guilty for not stepping into harm’s way again," Kissinger says — they are determined to rebuild. Wherever they are.